GB1393257A - Douplings - Google Patents

Abstract

1393257 Locking nuts and bolts; pipe couplings ROLLS-ROYCE (1971) Ltd 12 Jan 1973 [21 Jan 1972] 3000/72 Headings F2H and F2G Relative rotation between two members in screw-threaded engagement with one another is frictionally resisted by a locking element 10 or 30 carried by one member and having a non- circular cylindrical surface which engages at discrete areas of contact with a non-threaded cylindrical surface of the other member. In Fig. 1, a locking ring 10 of slightly elliptical form is housed in an annular groove 7 in a shoulder 6 of a bolt head 1, and contacts the smooth cylindrical wall of a recess 9 in an article 5. A ring shaped to have three or more areas in contact with the wall may alternatively be used. In Fig. 3a, the locking ring 10 is housed in a longitudinal extension of a nut 15 and engages an unthreaded surface 17 at the end of the shaft. In Fig. 4a, not shown, the surface 17 is on the side of the shaft threaded portion away from the shaft end. The ring 10 may alternatively be housed in a groove in the shaft and contact a smooth inner cylindrical wall of the nut extension (Figs. 3b and 4b, not shown). In a pipe coupling, Fig. 5, the ring 10 is housed in a groove in the wall of one pipe 25 and contacts an internal cylindrical surface of an axial extension 23 of a nut 20. A lip 22 of the nut clamps the end flange 27 of a second pipe 28. Again, the ring may be housed in a groove in the nut extension (Fig. 6, not shown). In Fig. 7, the locking ring 30 is a sleeve engaging outer cylindrical surfaces of the nut 35 and the pipe end, the points of contact with the nut being circumferentially offset from those with the pipe. The sleeve may be secured or clamped to the nut or to the pipe or bolt. A modified sleeve (Fig. 9, not shown), is clamped to a pipe end and has axially extending fingers which frictionally engage the outer surface of the nut.